From the publication “Optical Millimeter-Wave Systems for Broadband Mobile Communication, Devices and Techniques” by R.-P. Braun and G. Grokopf, published at the “International Zurich Seminar of Broadband Communications-Accessing, Transmission, Networking” at the ETH Zürich in February 1998, it is known that microwave frequencies may be generated by the superimposition of optical waves of semiconductor lasers of different wavelength in a transmitter, modulated, and transmitted.